DESCRIPTION: Previous studies have reported postoperative declines in cognitive performance in cardiopulmonary bypass (CPB) patients. Unfortunately, these studies relied on assessment instruments and research designs that did not permit specific conclusions about the underlying cognitive changes responsible for these performance declines. This research program will analyze the neuropsychological consequences of CPB using state-of-the-art, computerized, cognitive tests. Unlike the paper and pencil instruments routinely used in such studies, this test battery was designed to distinguish the roles of sensorimotor (i.e., non-associative) and cognitive (i.e., associative) processes in postoperative performance changes. Tests of psychomotor speed, attention, and memory are used to compare pre- (1-3 days) and postoperative (2-3 weeks and 6 months) performance on CPB patients with that of healthy control subjects, non-CPB vascular surgery patients, and heart disease patients treated with percutaneous transluminal coronary angioplasty (PCTA). Another unique aspect of this program is that it analyzes the relationship between patients' self-appraisals of performance and objective measures of performance. Previous studies have reported that CPB patients who most frequently complained of postoperative deficits were not the ones in whom deficits were most likely to be measured. It is hypothesized that subjective awareness of a postoperative performance deficit will depend upon whether the affected underlying neuropsychological processes are declarative or non-declarative in nature. Finally, recent research has revealed that calcium channel blockers have neuroprotective effects in patients exposed to cerebral insults. Although about 1 in 3 CPB patients receives calcium channel blockers for the treatment of heart disease, only one published study has examined the potential neuroprotective effects of calcium channel blockers in bypass patients. This program will systematically analyze the relationship between use of calcium channel blockers and the neuropsychological consequences of CPB. In summary, the central goals of this research program are to more precisely delineate the nature of the cognitive changes associated with CPB, identify the factors that determine the patient's awareness of postoperative changes, and evaluate the potential neuroprotective effects of calcium channel blockers in CPB patients. It is anticipated that this research program will contribute significantly both to the evaluation of new surgical technologies and to the understanding of how to best manage variables critical to preserving cerebral function during CPB.